Martha Diamond didn’t exactly work in obscurity. A downtown painter who died last year at age 79, she went to college with the critic Peter Schjeldahl, credited the painter Joan Mitchell with changing her practice during a 1970 studio visit and had
“Martha,” a new documentary now on Netflix, offers a candid portrait of the rise and fall (and rebirth?) of the homemaker extraordinairecrazywin, who last year, at 81, appeared on the cover of Sports Illustrated. The film, by R.J. Cutler, touches on